• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.7
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• pp.681-687
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• 2005

Experimental results for heat transfer characteristic and pressure gradients of HCs refrigerants R-290, R-600a, R-1270 and HCFC refrigerant R-22 during evaporating inside horizontal double pipe heat exchangers are presented. The test sections which has one tube diameter of 12.70 m with 0.86 mm wall thickness, another tube diameter of 9.52 mm with 0.76 mm wall thickness are used for this investigation. The local evaporating heat transfer coefficients of hydrocarbon refrigerants were higher than that of R-22. The average evaporating heat transfer coefficient increased with the increase of the mass flux. It showed the higher values in hydrocarbon refrigerants than R-22. Hydrocarbon refrigerants have higher pressure drop than R-22 in 12.7 mm and 9.52 mm. This results form the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air- conditioning systems.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.439-440
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• 2008

An inductive coupler, which feeds communication to the electric power transmission line, is required to establish Power Line Communication(PLC). The electro-magnetic property of magnetic core and design technology for coupler are very important to manufacture an inductive coupler for power transmission line. The magnetic core with superior electro-magnetic property was manufactured by using nano-crystalline alloy and an inductive coupler, which can operate at the maximum 2,000 A current, was designed and manufactured by establishment of current saturation, signal out winding, and electro-magnetic simulation in this study. Communication speed of 14 Mbps in 600 m communication distance of the real electric power transmission line was obtained by using the inductive coupler and application possibility of the inductive coupler for the electric power transmission line was certified.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.5
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• pp.754-761
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• 2004

In this paper, evaporating heat transfer characteristics in the refrigeration and air-conditioning facilities were studied using the environmentally friendly refrigerants R-1270 (Propylene). R-290 (Propane). R-600a (Iso-butane) and HCFC refrigerant R-22 The test tube was surrounded by an annulus with water flowing counter to the refrigerant. The tube is copper. with an outside diameter of 12.7mm and the wall thickness of 1.315mm. The test results showed that the local evaporating heat transfer coefficients of hydrocarbon refrigerants were superior to that of R-22 and the maximum increasing rate of heat transfer coefficient was found in R-1270. The average evaporating heat transfer coefficient increased with the increase of the mass velocity and it showed the higher values in hydrocarbon refrigerants than R-22 Comparing the heat transfer coefficient of experimental results with that of other correlations. the presented results had agood agreement with the Kandlikar's correlation. This results form the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air-conditioning systems.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1143-1148
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• 2005

Experimental results for heat transfer characteristic and pressure gradient of HCs refrigerants R-290, R-600a, R-1270 and HCFC refrigerant R-22 during condensing inside horizontal double pipe heat exchangers are presented. The test sections which have one tube diameter of 12.70 mm with 0.86 mm wall thickness, another tube diameter of 9.52 mm with 0.76 mm wall thickness are used for this investigation. The local condensing heat transfer coefficients of hydrocarbon refrigerants were higher than those of R-22. The average condensing heat transfer coefficient increased with the increase of the mass flux. It showed the higher values in hydrocarbon refrigerants than R-22. Hydrocarbon refrigerants have higher pressure drop than those of R-22 in 12.7 mm and 9.52 mm. This results from the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air-conditioning systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.12
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• pp.977-983
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• 2006

Experimental results for heat transfer characteristic and pressure gradient of hydrocarbon refrigerants (R-290, R-600a, R-1270) and HCFC refrigerant (R-22) during condensation inside horizontal double pipe heat exchangers are presented. The test sections which have one tube diameter of 12.70 mm with 0.89 mm, 9.52 mm with 0.76 mm, 6.35 mm with 0.13 mm wall thickness are used for this investigation, respectively. The local condensing heat transfer coefficients of hydrocarbon refrigerants were higher than those of R-22. The average condensing heat transfer coefficient increased with the increase of the mass flux. It showed the higher values in hydrocarbon refrigerants than R-22. Hydrocarbon refrigerants have higher pressure drop than R-22 in 10.92 mm, 8 mm and 6.1 mm inner diameters. These results from the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air-conditioning systems.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.1989-1992
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• 2014

Background: The aim of this study was to assess the response rates (clinical and pathological ) with docetaxel and epirubicin combination chemotherapy and its effect on outcome. Materials and Methods: We retrospectively analysed locally advanced breast cancer (LABC) patients who received NACT from January 2008 to December 2012 in our tertiary care centre. LABC constituted 37% of all breast cancer cases and 120 patients fulfilled the eligibility criteria. The regimens used for NACT were, six cycles of DEC (docetaxel $75mg/m^2$, epirubicin $75mg/m^2$, cyclophosphamide $50mg/m^2$ on Day 1, 3 weekly) and a sequential regimen (4 cycles of FEC, 5-flurouracil $600mg/m^2$, epirubicin $75mg/m^2$, cyclophosphamide $600mg/m^2$ followed by 4 cycles of docetaxel $85mg/m^2$). Results: The median age was 47 years (range 23-72). Ninety six ( 80 %) had T4 disease and 90% had clinically palpable lymph nodes at diagnosis. The median size of primary tumor at presentation was 5.9 cm. Hormone receptor positivity was seen in 55% and HER2/neu positivity, in 25%. Triple negative breast cancers constituted 25 % of the cases. The overall clinical response rate (complete or partial ) was 85% and pathological complete responses were obtained in 15%. Four cases defaulted, 5 patients died of treatment related toxicity and 15% developed febrile neutropenia on DEC. The median duration of follow up was 22 months. The median time to relapse was 20 months and the 3 year relapse free and overall survival rates were 50% and 70% respectively. Conclusions: LABC constituted 37% of all breast cancer cases at our institute. With NACT, pCR was seen in 15% of the cases. Sequential chemotherapy was better tolerated than concurrent anthracyline and taxane chemotherapy with a similar pCR.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.120-125
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• 2014

In this paper, suitable working fluid of 1MW Organic Rankine Cycle(ORC) with liquid-vapor ejector using effluent from power plant is selected. The results of comparison performance of 5 refrigerants are as follows; R600a, R134a, R1270, R236fa, R235fa. The operating parameters considered in this study include the condensation capacity evaporation capacity and efficiency. As a result of comparison of basic ORC system and with liquid-vapor ejector, with ORC system presents the higher system efficiency since the ejector makes the turbine outlet pressure lower than condensation pressure through its pressure recovery. Also, this ejector ORC system is advantageous in miniaturizing the size of components owing to decrease of evaporation capacity and condensation capacity.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.131-136
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• 1998

This experiment was carried out to investigate the effect of several organic fertilizers on the growth and root yield of Achyranthes japonica N. from 1995 to 1996. Four organic fertilizers were applied: rice straw manure (RSM), fermented rice straw manure (FRSM), mixed oil cake manure (MOCM) and mighty soil manure (MSM). Organic matter, available phosphate, $K_2O$, CaO, and MgO of soil increased in all plots with the addition of organic fertilizers, specifically with MOCM application. The highest contents of total nitrogen were 6.16% for MOCM and the available phosphate contents were very high in all of organic fertilizers except MSM. RSM and MSM with C/N ratios of 22.5, 17.7, respectively, were easily decomposed but C/N ratios of FRSM and MOCM, which were considered as irresolvable organic fertilizers, were 40.9 and 8.4, respectively. FRSM and MOCM applications increased emergence rate and improved the growth characters of shoot and root parts of plants compared to those of N - P - K fertilization. The highest dry root yield resulted from FRSM 20% and MOCM 26% treatment. There were significantly positive correlations between the growth characters of shoot, root parts of plants and dry root yield in A. japonica grown under organic fertilizer applications.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.44-48
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• 1994

A new method of quaternion feedback control for the attitude acquisition of spacecraft is suggested to limit the angular rates of rigid body which are not desirable and make a control algorithm complicate. New attitude acquisition control algorithm is evaluated and compared with the existing quaternion feedback control method for the large slewing maneuvers through simulations. The simulation results reveal that a new method is effective on limiting the angular rates of spacecraft.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.2
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• pp.57-62
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• 2018

In this study, we investigated the impurity effect of $Ga_2O_3$ doped thin film by simple doping method using Mg acetate solution. Both undoped $Ga_2O_3$ thin films and Mg-doped $Ga_2O_3$ thin films were grown on Si substrates at 600 and $900^{\circ}C$ for 30 minutes by means of a customized MOCVD method. As a result of the surface analysis, there were no obvious morphological differences by Mg impurity implantation. The surface of the thin film grown at $900^{\circ}C$ was rougher than those grown at $600^{\circ}C$ and polycrystallization was achieved. As a result of the optical property analysis, in the case of the doped sample, the overall emission peak was red shifted and the UV radiation intensity was increased. As a result of the I-V curve, the leakage current of the $600^{\circ}C$ growth thin film decreased by the Mg impurity and the photocurrent of the growth thin film of $900^{\circ}C$ increased.